esp-idf/components/driver/esp32c3/rtc_tempsensor.c

160 lines
5.5 KiB
C

// Copyright 2016-2018 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <esp_types.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "esp_log.h"
#include "hal/adc_ll.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/apb_saradc_struct.h"
#include "soc/apb_saradc_reg.h"
#include "soc/system_reg.h"
#include "driver/temp_sensor.h"
#include "regi2c_ctrl.h"
#include "esp32c3/rom/ets_sys.h"
#include "esp_efuse_rtc_calib.h"
static const char *TAG = "tsens";
#define TSENS_CHECK(res, ret_val) ({ \
if (!(res)) { \
ESP_LOGE(TAG, "%s(%d)", __FUNCTION__, __LINE__); \
return (ret_val); \
} \
})
#define TSENS_XPD_WAIT_DEFAULT 0xFF /* Set wait cycle time(8MHz) from power up to reset enable. */
#define TSENS_ADC_FACTOR (0.4386)
#define TSENS_DAC_FACTOR (27.88)
#define TSENS_SYS_OFFSET (20.52)
typedef struct {
int index;
int offset;
int set_val;
int range_min;
int range_max;
int error_max;
} tsens_dac_offset_t;
static const tsens_dac_offset_t dac_offset[TSENS_DAC_MAX] = {
/* DAC Offset reg_val min max error */
{TSENS_DAC_L0, -2, 5, 50, 125, 3},
{TSENS_DAC_L1, -1, 7, 20, 100, 2},
{TSENS_DAC_L2, 0, 15, -10, 80, 1},
{TSENS_DAC_L3, 1, 11, -30, 50, 2},
{TSENS_DAC_L4, 2, 10, -40, 20, 3},
};
static float s_deltaT = NAN; // unused number
esp_err_t temp_sensor_set_config(temp_sensor_config_t tsens)
{
REG_SET_BIT(SYSTEM_PERIP_CLK_EN1_REG, SYSTEM_TSENS_CLK_EN);
CLEAR_PERI_REG_MASK(ANA_CONFIG_REG, ANA_I2C_SAR_FORCE_PD);
SET_PERI_REG_MASK(ANA_CONFIG2_REG, ANA_I2C_SAR_FORCE_PU);
REGI2C_WRITE_MASK(I2C_SAR_ADC, I2C_SARADC_TSENS_DAC, dac_offset[tsens.dac_offset].set_val);
APB_SARADC.apb_tsens_ctrl.tsens_clk_div = tsens.clk_div;
APB_SARADC.apb_tsens_ctrl2.tsens_xpd_wait = TSENS_XPD_WAIT_DEFAULT;
APB_SARADC.apb_tsens_ctrl2.tsens_xpd_force = 1;
ESP_LOGD(TAG, "Config temperature range [%d°C ~ %d°C], error < %d°C",
dac_offset[tsens.dac_offset].range_min,
dac_offset[tsens.dac_offset].range_max,
dac_offset[tsens.dac_offset].error_max);
return ESP_OK;
}
esp_err_t temp_sensor_get_config(temp_sensor_config_t *tsens)
{
TSENS_CHECK(tsens != NULL, ESP_ERR_INVALID_ARG);
CLEAR_PERI_REG_MASK(ANA_CONFIG_REG, ANA_I2C_SAR_FORCE_PD);
SET_PERI_REG_MASK(ANA_CONFIG2_REG, ANA_I2C_SAR_FORCE_PU);
tsens->dac_offset = REGI2C_READ_MASK(I2C_SAR_ADC, I2C_SARADC_TSENS_DAC);
for (int i = TSENS_DAC_L0; i < TSENS_DAC_MAX; i++) {
if (tsens->dac_offset == dac_offset[i].set_val) {
tsens->dac_offset = dac_offset[i].index;
break;
}
}
tsens->clk_div = APB_SARADC.apb_tsens_ctrl.tsens_clk_div;
return ESP_OK;
}
esp_err_t temp_sensor_start(void)
{
REG_SET_BIT(SYSTEM_PERIP_CLK_EN1_REG, SYSTEM_TSENS_CLK_EN);
APB_SARADC.apb_tsens_ctrl2.tsens_clk_sel = 1;
APB_SARADC.apb_tsens_ctrl.tsens_pu = 1;
return ESP_OK;
}
esp_err_t temp_sensor_stop(void)
{
APB_SARADC.apb_tsens_ctrl.tsens_pu = 0;
APB_SARADC.apb_tsens_ctrl2.tsens_clk_sel = 0;
return ESP_OK;
}
esp_err_t temp_sensor_read_raw(uint32_t *tsens_out)
{
TSENS_CHECK(tsens_out != NULL, ESP_ERR_INVALID_ARG);
*tsens_out = APB_SARADC.apb_tsens_ctrl.tsens_out;
return ESP_OK;
}
static void read_delta_t_from_efuse(void)
{
uint32_t version = esp_efuse_rtc_calib_get_ver();
if (version == 1) {
// fetch calibration value for temp sensor from eFuse
s_deltaT = esp_efuse_rtc_calib_get_cal_temp(version);
} else {
// no value to fetch, use 0.
s_deltaT = 0;
}
ESP_LOGD(TAG, "s_deltaT = %f", s_deltaT);
}
static float parse_temp_sensor_raw_value(uint32_t tsens_raw, const int dac_offset)
{
if (isnan(s_deltaT)) { //suggests that the value is not initialized
read_delta_t_from_efuse();
}
float result = (TSENS_ADC_FACTOR * (float)tsens_raw - TSENS_DAC_FACTOR * dac_offset - TSENS_SYS_OFFSET) - s_deltaT / 10.0;
return result;
}
esp_err_t temp_sensor_read_celsius(float *celsius)
{
TSENS_CHECK(celsius != NULL, ESP_ERR_INVALID_ARG);
temp_sensor_config_t tsens;
uint32_t tsens_out = 0;
esp_err_t ret = temp_sensor_get_config(&tsens);
if (ret == ESP_OK) {
ret = temp_sensor_read_raw(&tsens_out);
printf("tsens_out %d\r\n", tsens_out);
TSENS_CHECK(ret == ESP_OK, ret);
const tsens_dac_offset_t *dac = &dac_offset[tsens.dac_offset];
*celsius = parse_temp_sensor_raw_value(tsens_out, dac->offset);
if (*celsius < dac->range_min || *celsius > dac->range_max) {
ESP_LOGW(TAG, "Exceeding the temperature range!");
ret = ESP_ERR_INVALID_STATE;
}
}
return ret;
}